Switching configurations such as, e.g., power supply systems are pervasive in many electronic applications from computers to automobiles. Generally, voltages within a power supply system are generated by performing a DC-DC, DC-AC, and/or AC-DC conversion by operating a switch loaded with an inductor or transformer. In some power supply systems, combinations of switches are arranged in a bridge configuration such as a half-bridge, full-bridge, or a multi-phase bridge. When very high voltages are generated by the power supply, it is beneficial to use switches that have both a high breakdown voltage and a low on-resistance.
In high current bridge configuration applications, electronic switches may be used to couple a load to a high-side or a low-side supply line. Mostly, n-channel power MOSFETs are used as switches in such applications, but other kinds of switches are possible as well. In order to be able to drive the gates and the gate charges of these switches very fast, so called bridge driver integrated circuits (ICs) are used. An alternating switching of the high-side and low-side switches is achieved by using a pulse width modulated (PWM) signal, which defines the load current at the output of the bridge with its duty cycle.
During the operation of such bridge drivers, the current flowing through the electronic switches may be measured using a current monitor circuit coupled to the bridge circuit. The output of the current monitor circuit may be used to shut down the bridge driver upon detection of an overcurrent condition such as a short circuit.